A very bright Sun-grazing comet was discovered by SOHO while a pair of
coronal
mass ejections are heading for Earth following two explosions above sunspot
9672
on Monday, Oct. 22nd. The expanding cloud(s) will likely strike our
planet's
magnetosphere on Oct. 24th or 25th and trigger a new round of geomagnetic
activity.

A Sun-grazing comets was spotted in the LASCO C3 field and can be seen
moving towards the Sun from lower right while the Earth directed CME blast
out
from the Sun as seen in this mpeg animation:

The comets tail grows as it approaches the Sun and a long tail can be seen
in
the images and animation from the LASCO C2 field of view. This is one of the
brightest comets observed by SOHO:

Here is one still image of the comet.
In all these images the shaded disk is a mask in the instrument that blots
out
direct sunlight. The white circle added within the disk shows the size and
position of the visible Sun.

SOHO has discovered more than 365 comets in just under 6 years which makes
SOHO
the most prolific comet finder in the history of astronomy.

Solar radiation heats the comet which in turn causes the outgassing of the
water
molecules and dust. The dust scatters sunlight at visible
wavelengths, making the comet bright in LASCO images. The water molecules
break
down into oxygen and hydrogen atoms, and the
hydrogen atoms interact with the coronal plasma.

IMAGE CREDITS: SOHO (ESA/NASA)

Launched almost 6 years ago as a project of international cooperation
between
the European Space Agency and
NASA, the Solar and Heliospheric Observatory has revolutionized the science
of
the Sun.